Parison for forming blow molded medical balloon with modified portion, medical balloon, and related methods

ABSTRACT

A parison for being blow molded into a medical balloon for a catheter includes a first tubular layer having a functional modification and a second tubular layer adapted for bonding with the first tubular layer to form the blow molded balloon. Related methods are also disclosed.

The following U.S. patent applications are incorporated by reference:61/608,852; 61/608,859; 61/608,862; 61/608,897; 61/608,902; 61/608,908;61/608,913; 61/608,917; 61/608,927; 61/608,932; 61/608,941; and61/747,444.

TECHNICAL FIELD

This disclosure relates generally to balloons for performing medicalprocedures, such as angioplasty and, more particularly, to a parison forforming a blow molded medical balloon having a modified portion, such asa layer that is radiopaque, a medical balloon, and related methods.

BACKGROUND OF THE INVENTION

Balloons are routinely used to resolve or address flow restrictions orperhaps even complete blockages in tubular areas of the body, such asarteries or veins. In many clinical situations, the restrictions arecaused by hard solids, such as calcified plaque, and require the use ofhigh pressures to compact such blockages. Commercially availableballoons employ complex technology to achieve high pressure requirementswithout sacrificing the profile of the balloon. Besides high pressurerequirements, the balloons should also be resistant to puncture, easy totrack and push, and present a low profile, especially when used forangioplasty.

In clinical practice, angioplasty balloons are expanded from a deflated,folded state to an expanded state within a vessel to treat a targetarea, such as a portion of the circumferential inner wall I of a bloodvessel V, as shown in FIGS. 1 and 2. The inflation of a balloon 12 withwall 28 is traditionally completed using an X-ray contrast agent CMalong dimension DX to provide better visibility under X-ray or otherform of radiography R during the interventional procedure, asillustrated in FIGS. 3 and 3 a (which shows the intensity measured by afluoroscope detector plate, FDP). Typically, a 70/30 percent mixture ofcontrast agent and saline is used to inflate the balloon during anangioplasty procedure.

In general, a desirable goal is to reduce inflation and deflation timesrequired for balloons without sacrificing the profile of the balloons,especially for large volume balloons (which can require up to twominutes of inflation/deflation times with the contrast agent). Becauseof its relatively high viscosity, it would also be desirable toeliminate, or at least reduce the amount of the contrast agent used ininflation/deflation of the balloons. The use of contrast agent prolongsthe inflation/deflation times and also poses the risk of iodine exposureto patients sensitive to iodine. In this regard, a non-radiopaquesubstance could be used in lieu of the contrast agent, such as forexample saline or carbon dioxide, but such substances are invisibleduring X-ray imaging, and thus do not enhance visibility.

Furthermore, the physician performing the angioplasty procedure shouldbe able to locate the position of the uninflated balloon with accuracy,so that the balloon will be properly positioned once inflated. This isconventionally accomplished by attaching marker bands on the cathetershaft in the region corresponding to the balloon working surface. This“working surface” is the surface along the portion of the balloon thatis used to achieve the desired treatment effect, such as contacting thecalcified plaque (which surface in the case of a balloon having conicalor tapering sections at the proximal and distal ends is typicallyco-extensive with a generally cylindrical barrel section).

Misalignment of the marker bands during placement along the shaftsometimes results in their failure to correspond precisely to the extentof the working surface, as is shown in FIG. 4 (note misalignment amountX between each interior marker band M carried by shaft S and workingsurface W of balloon 12, which also typically includes a radiopaque tipP at the distal end). Even upon exercising great care to position themarkers properly on the underlying shaft in alignment with anticipatedboundaries of the working surface when the balloon is inflated, thereremains a tendency for mismatch clue to several possible factors. Onesuch factor may be the tolerance stack-ups arising as a consequence ofthe affixation of the balloon to the distal end of the catheter shaft.The balloon also has a tendency to grow in the longitudinal directionwhen inflated, especially with large and particularly long balloons.Another factor is the tendency of the portion of the catheter shaftwithin the balloon to bend or flex during inflation. This may lead tomisalignment between radiopaque markers fixed to the shaft and theworking surface.

Whatever the cause, the resulting misalignment may prevent the clinicianfrom accurately identifying the location of the working surface of theballoon during an interventional procedure. This may lead to ageographic misplacement, or “miss,” of the intended contact between thetarget area T and the working surface W of the balloon 12 (see FIG. 2).It is especially desirable to avoid such an outcome when the balloon isdesigned to deliver a payload (such as a drug, stent, or both) or aworking element to a specified location within the vasculature, since amiss may prolong the procedure (such as, for example, by requiringredeployment of the balloon 12 or the use of another balloon catheter inthe case of a drug coated balloon).

Upon deflation, the balloon may also be subject to a phenomenon known as“pancaking.” In this condition, the balloon 12 folds down upon itself toa flattened state, as shown in FIG. 5. This situation may cause theballoon to be viewed through fluoroscopy as perhaps still being in theinflated condition, since the full width of the balloon may still beperceived. This can give the clinician the false perception that theballoon remains inflated, when in fact it is not.

Accordingly, the need is identified for a balloon for which the workingsurface may be identified during an interventional procedure withenhanced precision. The solution would take into account the possiblemismatch between fixed locations on the catheter shaft and the balloonto define the working surface, and would operate independent of theposition of the portion of the catheter shaft within the balloon. Theimproved identification may also allow for the better detection of thefalse perception of deflation caused by pancaking. Overall, proceduralefficiency would be enhanced without remarkably increasing cost orcomplexity, and in a manner that can be applied to many existingcatheter technologies without extensive modification.

SUMMARY OF THE INVENTION

An object of the disclosure is to provide a balloon for which theworking surface may be identified during an interventional procedurewith enhanced precision.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-9 are illustrative of the background of the invention;

FIG. 10 illustrates a first embodiment according to the disclosure;

FIGS. 11-11 a and 12-12 a show a manufacturing technique for forming theFIG. 10 embodiment;

FIGS. 13 and 14 further shown manufacturing techniques;

FIG. 15 illustrates a further embodiment according to the disclosure;

FIGS. 16 and 17 illustrate another embodiment according to thedisclosure;

FIGS. 18-21 show still further embodiments;

FIGS. 22 and 22 a are cross-sectional side and end views of anotherembodiment;

FIG. 23 is a side view of a balloon catheter formed according to oneaspect of the disclosure;

FIGS. 24 and 25 show a further embodiment; and

FIGS. 26-28 show still a further embodiment.

MODES FOR CARRYING OUT THE INVENTION

The description provided below and in regard to the figures applies toall embodiments unless noted otherwise, and features common to eachembodiment are similarly shown and numbered.

Provided is a catheter 10 having a distal portion 11 with a balloon 12mounted on a catheter tube 14. Referring to FIGS. 6, 7, and 8, theballoon 12 has an intermediate section 16, or “barrel,” and end sections18, 20. In one embodiment, the end sections 18, 20 reduce in diameter tojoin the intermediate section 16 to the catheter tube 14 (and thussections 18, 20 are generally termed cones or cone sections). Theballoon 12 is sealed at balloon ends (proximal end 15 a and distal end15 b) on the cone sections 18, 20 to allow the inflation of the balloon12 via one or more inflation lumens 17 extending within catheter tube 14and communicating with the interior of the balloon 12.

The catheter tube 14 also includes an elongated, tubular shaft 24forming a guidewire lumen 23 that directs the guidewire 26 through thecatheter 10, and along the distal end of which the balloon 12 may belocated. As illustrated in FIG. 8, this guidewire 26 may extend throughthe proximal end of the catheter 10 and a first port 25 of a connector27 into the lumen 23 to achieve an “over the wire” (OTW) arrangement,but could also be provided in a “rapid exchange” (RX) configuration, inwhich the guidewire 26 exits a lateral opening 14 a closer to the distalend (see FIG. 9) or else is fed through the tip at a passage distally ofthe balloon 12 (“short” RX; not shown). A second port 29 may also beassociated with catheter 10, such as by way of connector 27, forintroducing a fluid (e.g., saline, a contrast agent, or both) into theinterior compartment of the balloon 12 via the inflation lumen 17.

Balloon 12 may include a single or multi-layered balloon wall 28 formingthe interior for receiving the inflation fluid. The balloon 12 may be anon-compliant balloon having a balloon wall 28 that maintains its sizeand shape in one or more directions when the balloon is inflated.Examples of non-compliant balloons may be found in U.S. Pat. No.6,746,425 and Publication Nos. US 2006/0085022, US 2006/0085023 and US2006/0085024, the disclosures of which are hereby incorporated herein byreference. The balloon 12 in such case also has a pre-determined surfacearea that remains constant during and after inflation, also has apre-determined length and pre-determined diameter that each, ortogether, remain constant during and after inflation. The balloon 12could also be semi-compliant or compliant instead, depending on theparticular use.

In order to provide for enhanced locatability during an interventionalprocedure, the balloon 12 may have a modified portion having aradiopaque quality. In one embodiment, this radiopaque quality isprovided in a manner that allows for a clinician to differentiate, withrelative ease and high precision, one portion of the balloon 12 fromanother (such as, but not limited to, the barrel section 16 includingthe working surface W from the cone sections 18, 20). This helps theclinician ensure the accurate positioning of the balloon 12 and, inparticular, a portion of or the entire working surface W, at a specifiedtreatment location, which may be especially desirable in the delivery ofdrugs via the balloon working surface W, as outlined in more detail inthe following description.

In one embodiment, and with initial reference to FIG. 10, the radiopaquequality is achieved by providing one or more at least partiallyradiopaque markings 30. The marking or markings 30 may be provided alongthe balloon 12 to create a defined portion as the working surface W, ascontrasted with the full length L of the balloon. For example, a marking30 extend along the balloon 12 in a longitudinal direction along thebarrel section 16 and over the entire circumference of the workingsurface W. Alternatively, the marking 30 may extend over only a portionof the working surface W, or may extend over only a different part ofthe balloon 12 (such as the cone sections 18, 20), as outlined furtherin the following description.

This marking 30 may be provided during a process used to form theballoon 12 having the desired shape created by a multi-layered wall 28.In particular, a first tube 50 comprising a thin layer of material (suchas a polymer), may be inserted within a second tube 52, to form aparison 54, as shown in FIG. 11 (perspective view) and 11 a(cross-section). The second tube 52 may also comprise a compatiblepolymeric material, but could also be formed of a different material(such as metal, including possibly a film). The second tube 52 includesthe one or more radiopaque markings 30, which may correspond in lengthto the barrel section 16 of the finished balloon, as shown in FIG. 11(but the second tube could extend the entire length of the balloon 12,as discussed below and illustrated by inner tube 62 in FIG. 18). Thefirst, inner tube 50 may then be expanded to form a multi-layeredballoon 12 (FIG. 12), with the second, outer tube 52 thus forming aradiopaque outer sleeve, as shown in the cross-sectional view of FIG. 12a.

Turning to FIG. 13, it can be understood that this processing may beachieved using a blow mold 55 having separable portions forming a moldcavity 56 corresponding in shape to the desired shape of the balloon.The outer tube 52 may be pre-positioned in the mold cavity 56, includingpossibly within a correspondingly shaped recess formed along one or moreof the interior surfaces of the mold 55. The inner tube 50 may then beexpanded using heat and pressure to form the balloon 12 with the desiredshape, and having the outer tube 52 intimately bonded to it.

FIG. 14 shows that, instead of a single tube 52, two spaced tubes, suchas radiopaque collars 52 a, 52 b, may be provided on the inner tube 50in order to provide spaced markings 30 on the finished balloon 12 (seeFIG. 19). Like tube 52, these collars 52 a, 52 b may be pre-positionedin the mold cavity 56 so as to receive the inner tube 50 when inserted.As noted above for tube 52, the collars 52, 52 b may be comprised of athin flexible, material (e.g., a polymer, such as nylon) compatible withthe material (e.g., a polymer, such as nylon) of the adjacent layerformed by tube 50, but could also be made of different materials, suchas one or more metal foils. Upon expanding the inner tube 50, thecollars 52 a, 52 b are intimately bonded to form a balloon 12 withspaced, radial markers, which as the result of the positioning atpre-determined locations in the mold cavity 56 may align precisely withthe edges of the working surface W.

The markings 30 may be provided on the tube 52 (or tubes 52 a, 52 b) invarious ways. For example, the markings 30 may be provided by applying aradiopaque material to the tube 52 at the desired location in any shape,pattern or form (including possibly alphanumeric characters to provideinformation that can be perceived under fluoroscopy, such as a length,diameter, logo, trademark, rated burst pressure, or balloon type). Thismay be done by inking, spraying, printing, or painting the radiopaquematerial in fluid form on the surface of the tube 52 (possibly with theapplication of a mask or the like, in which case the techniques ofdipping or rolling in the radiopaque material to form the desiredcoating could be used). Alternatively, the marking 30 may be embedded inthe tube 52, including for example by providing it as part of a film, orin a bonding agent or adhesive used to bond multiple layers together toform the tube 52 (see, e.g., U.S. Patent Application Publication No.2011/0160661, the disclosure of which is incorporated herein byreference). The marking 30 may be provided during the process offabricating the tube 52, such as for example during a co-extrusionprocess. Examples of such techniques are described in a co-pendingapplication filed on the same date as this application, “MEDICAL BALLOONWITH COEXTRUDED RADIOPAQUE PORTION,” listing as inventors Paul Fillmore,Justin Hall, Pat Byrne, Margo Underwood, the disclosure of which isincorporated herein by reference.

As perhaps best understood with reference to FIGS. 15 and 16, the moldcavity may be adapted to form the balloon 12 with the desired shape andappearance, and could also be adapted to form shoulders 12 a on theballoon 12 once blown. These shoulders 12 a may help to retain the outertube 52 providing the modified portion of the balloon 12 againstmovement in the longitudinal direction, and thus help to ensure that itremains positioned at the desired location (again, in one embodiment,aligned with the full extent of the working surface W). Additionally oralternatively, as shown in FIG. 17, the inner surface of the outer tube52 may be adapted for frictionally engaging the outer surface of thetube 50, such as by providing a roughened or textured surface 58.

Additionally or alternatively, an adhesive may be used to improve thebond between the tubes 50, 52. This adhesive may be provided on eithertube prior to blow molding. The adhesive may also optionally be providedwith a radiopacifier in order to enhance the radiopaque quality of theballoon 12 (see, e.g., U.S. Patent Application Publication No.2011/0160661).

Another embodiment involves forming the balloon 12 with a modifiedportion by blow molding a multi-layered parison, wherein at least one ofthe layers of the parison comprises a radiopaque material. Thus, forexample, a parison 60 in this embodiment may include an inner layercomprising a radiopaque film 62, and an outer layer 64 comprising atraditional film that is not made radiopaque by an additive. The blowmolding process expands the parison 60 to thus form a balloon 12 havinga radiopaque quality corresponding to the length of the inner layerincluding radiopacifier, which may be the full length L of the balloon12.

Balloons 12 that incorporate coatings comprising drugs to be applied tothe vasculature may also benefit from the above-referenced embodiments.For example, as shown in FIG. 19, a balloon 12 including a definedworking surface W, such as by providing radiopaque markings 30 at thetransitions between the barrel section 16 and cone sections 18, 20, mayinclude a portion coated with such a drug D, such as one designed forachieving a desired therapeutic effect when applied to the interior ofthe vessel. The radiopaque marking 30 may also correspond to thelocation of the drug D on the balloon 12, such as along the entireworking surface W or only a portion of it. The drug D may be applied tothe inflated balloon as part of the manufacturing process, and prior tofolding for insertion in the vasculature. The clinician may thus withthe benefit of a fluoroscope determine the precise positioning of theworking surface W prior to inflating the balloon 12 in the vasculatureto deliver the drug D to the desired location and provide the desiredtreatment regimen.

The markings 30 may also be provided as one or more longitudinal strips66 that do not extend along the entire circumference of the balloon 12,as shown in FIGS. 20 and 21. This may be achieved by providing one orboth of the layers 62, 64, or the tube 52, with radiopaque materialcorresponding to the strips 66, such as by a co-extrusion process.Additional details are provided in a concurrently filed patentapplications entitled, “MEDICAL BALLOON WITH RADIOPAQUE IDENTIFIER FORPRECISELY IDENTIFYING THE WORKING SURFACE,” for inventors Sean Wall, PatByrne, Robert Righi, Angela Crall, Paul Wales, and Allan Ronan, and“MEDICAL BALLOON WITH RADIOPAQUE END PORTION FOR PRECISELY IDENTIFYING AWORKING SURFACE LOCATION,” for inventors Sean Wall, Scott Randall,Robert Righi, Angela Crall, the disclosures of which are incorporatedherein by reference. The presence of plural spaced markings 30 in thismanner may also help to distinguish between the inflated condition (inwhich the markings are spaced), and the properly deflated condition, asthe markings would be closer to each other when the balloon is folded.

In another embodiment, the blow molding operation may be arranged tocreate a balloon 12 with a different type of modified layer. Forexample, in FIG. 22, an insert 52 may be provided with a functionalmodification, such as an outer surface that is textured or etched, andassociated with an inner tube 50. The insert 52 could be made partiallyor fully radiopaque if desired (see, e.g., FIG. 10), but such isconsidered optional. In one embodiment, a multi-layered insert 52 may beprovided with an outer radiopaque layer 51 a and an inner support layer51 b that is not enhanced with a radiopacifier and exposed by theopenings 53 formed by etchings in the outer layer (see FIG. 22a ). Thismay create a particular pattern under fluoroscopy, which may allow forthe detection of the locations on the balloon 12 where a drug is present(either on the etched portions or the unetched portions, as desired,which again may correspond to the working surface W).

In any case, on blow molding the resulting parison 54 into acorresponding mold 55 (see FIGS. 13 and 14), a balloon 12 may be formedhaving an etched or textured outer surface layer 28 a of the balloonwall 28. This layer 28 a may extend along the entire working surface W,as shown in FIG. 23, or any portion of it. In the case of etching,texturing, or other surface features, the material forming the insert 52should have a sufficiently high melt flow index such that the featuresare not caused to disappear as the result of the heat and pressurecreated during the blow molding process.

Another example for creating a balloon 12 with a modified layer is toprovide an insert 52 with one or more openings. For example, as shown inFIG. 24, the insert 52 may be provided as a reticulated or fenestratedbody, such as a mesh, screen or lattice having a plurality of crossingmembers 57 forming openings 53. The body 52 may be tubular in form, asshown, and could comprise more than one piece or part (similar tocollars 52 a, 52 b). As above, the material forming the insert 52 shouldhave a sufficiently high melt flow index such that the features are notcaused to disappear as the result of the heat and pressure createdduring the blow molding process.

When arranged to form a parison 54 and blow molded together, the insert52 bonds to an inner tube 50 and forms an outer layer of the finishedballoon 12. In the case of an insert 52 as shown, the openings 53 exposethe balloon wall 28, which may be adapted to form the modified layer(such as by being radiopaque). The body 52 may extend along the entireworking surface W, and may optionally be fully or partially radiopaque.Alternatively, the body 52 may be provided with a coating, such as inthe form of a drug or an agent providing enhanced lubricity.

It is also possible to modify the mold 55 to provide a surface treatmenton the finished balloon 12. For example, as shown in FIG. 25, the innersurfaces of the mold cavity 56 may be provided with a textured pattern56 a, such as by etching, engraving, or the like, so as to form inwardlydirected projections. This includes along the portions corresponding tothe working surface W of the balloon 12 (e.g., the barrel section). Whena parison 54 (which may be a single layer of material), is then expandedin the mold cavity 56 (FIG. 26), the surface of the resulting balloon 12is provided with a corresponding pattern in the form of an impression ofthe pattern in the mold 55. In other words, the projections forming thepattern 56 a in the mold form depressions in the outer surface of theballoon wall 28.

An option in this embodiment is to deposit a material within the moldcavity 56 to partially or completely fill any spaces or gaps formed inthe pattern 56 a, such as for example a radiopacifier 59. As shown inFIGS. 27 and 28, the balloon 12 resulting from blow molding using a mold55 with this type of pattern 56 a with a filler would thus have asurface layer modified to including the selected filler material (whichin the case of a radiopacifier 59 would make the surface partiallyradiopaque, as shown by the darkened portions of the balloon wall 28 inFIG. 28). The depositing of the material within the mold 55 may be doneby injection through an internal passageway opening within the cavity56, either before or during the molding process, including possibly byspraying the filler material within the mold cavity 56 (such as when themating portions forming the mold 55 are separated to expose the surfacepattern 56 a).

Examples of radiopaque materials include, but are not limited to, finelydivided tungsten, tantalum, bismuth, bismuth trioxide, bismuthoxychloride, bismuth subcarbonate, other bismuth compounds, bariumsulfate, tin, silver, silver compounds, rare earth oxides, and manyother substances commonly used for X-ray absorption. The polymer usedfor making a film, possible with a radiopaque material, may be anypolymeric material which can be loaded with radiopacifier and formedinto a sufficiently thin film. Examples of polymers includethermoplastic and thermoset polymers. Some examples of thermoplasticpolymers include, but are not limited to, polyurethanes, polyamides(nylon 11, nylon 12), polyether-polyamide copolymers such as PEBAX,polyethylene terephthalate or other polyesters, polyvinyl acetate,polyvinyl chloride, and many other thermoplastic materials useful formaking films. Some examples of thermoset polymers include, but are notlimited to, cross linked polyurethanes, polyureas, epoxies, acrylics,silicones, and many other thermoset materials that can be formed intothin structures, including films. Any adjacent structures to be bonded,such as tubes 50, 52 or layers 62, 64, may be formed of compatiblematerials, which may avoid additional processing or the inclusion of acompatibilizer, tie layer or the like.

The invention may be understood with reference to the following items:

1. A parison for being blow molded into a medical balloon for acatheter, comprising:

-   -   a first tubular layer having a functional modification; and    -   a second tubular layer adapted for bonding with the first        tubular layer to form the blow molded balloon.

2. The parison of item 1, wherein the first layer is external to thesecond layer.

3. The parison of item 1, wherein the first layer is internal to thesecond layer.

4. The parison of any of the foregoing items, wherein the radiopaqueportion comprises a strip.

5. The parison of item 4, wherein the strip comprises a circumferentialband.

6. The parison of item 4 or 5, wherein the strip extends between a firstend and a second end of the first layer.

7. The parison of any of the foregoing items, wherein the first tubularlayer is spaced from the second tubular layer.

8. The parison of any of the foregoing items, wherein the functionalmodification is selected from the group consisting of an addedradiopacifier, a surface pattern, an etching, one or more perforations,and combinations of the foregoing.

9. A medical balloon comprising a generally cylindrical barrel sectionforming a working surface, and an at least partially radiopaque tubepositioned over the barrel section and extending substantially along theworking surface.

10. The balloon of item 9, further including first and second shouldersadjacent the proximal and distal ends of the radiopaque tube.

11. The balloon of item 9 or 10, wherein the entire tube is radiopaque.

12. The balloon of any of items 9 to 11 formed by the parison of any ofitems 1 to 8, comprising:

-   -   a tubular, inflatable body comprising a wall, the body including        first and second generally conical ends and the generally        cylindrical barrel section between the generally conical ends        and providing the working surface.

13. The balloon of item 12, wherein the first layer extends from thefirst end to the second end of the balloon.

14. The balloon of item 12, wherein the first layer extends along onlythe working surface.

15. The balloon of any of items 12 to 14, wherein the first layerextends along an entire circumference of a portion of the wall.

16. The balloon of any of items 12 to 15, wherein the first layerextends along the full circumference of the wall.

17. The balloon of any of items 12 to 16, wherein the wall includesfirst and second spaced shoulders, and wherein the first layer ispositioned between the shoulders.

18. The balloon of any of items 12 to 17, wherein the first and secondlayers both extend from a first end to a second end of the balloon.

19. A method of manufacturing an at least partially radiopaque balloon,comprising:

-   -   blow molding a first layer of a material having a functional        modification and a second layer of material together to form the        balloon.

20. The method of item 19, wherein the blow molding step comprisesproviding the first layer along an inner surface of the second layer.

21. The method of item 19, wherein the blow molding step comprisesproviding the first layer along an outer surface of the second layer.

22. The method of any of items 19 to 21, further including the step ofproviding the first layer of material that is shorter that the secondlayer of material in a longitudinal direction.

23. The method of any of items 19 to 22, further including the step ofproviding the first layer with a radiopaque portion in the form of atleast one strip.

24. The method of any of items 19 to 23, further including the step ofproviding the first layer with a substantially continuous radiopacity.

25. The method of any of items 19 to 24, further including the step ofproviding the first layer with the functional modification selected fromthe group consisting of an added radiopacifier, a surface pattern, anetching, one or more perforations, and combinations of the foregoing.

26. A method of manufacturing a medical balloon using a mold having amold cavity, comprising:

-   -   blow molding a parison at least partially within the mold cavity        of the mold to form a balloon having a modified outer portion        along a working surface of the balloon.

27. The method of item 26, wherein the blow molding step is preceded bythe step of providing a material for forming the modified portion in theblow mold.

28. The method of item 26 or 27, wherein the blow molding step ispreceded by the step of providing a tube for forming the modifiedportion in the blow mold.

29. The method of any of items 26 to 28, wherein the blow molding stepis preceded by the step of providing a fenestrated tube for forming themodified portion in the blow mold.

30. The method of any of items 26 to 29, wherein the blow molding stepis preceded by the step of providing a reticulated tube for forming themodified portion in the blow mold.

31. The method of any of items 26 to 30, wherein the mold cavityincludes a surface pattern, and the blow molding step creates themodified portion by contacting the parison with the surface pattern.

32. The method of any of items 26 to 31, wherein the mold cavityincludes a surface pattern and a filter material, and the blow moldingstep creates the modified portion by contacting the parison with thesurface pattern and the filler material.

33. The method of any of items 26 to 32, wherein the mold cavityincludes a surface pattern and a radiopaque material, and the blowmolding step creates the modified portion by contacting the parison withthe surface pattern and the radiopaque material.

34. A method for forming a balloon, comprising:

-   -   blow molding a radiopaque material to form the balloon.

The subject matter of each of the paragraphs below citing a balloon or acatheter can be part of a balloon or a catheter respectively that iscited in any of the other paragraphs:

1.1 A balloon catheter, comprising: an elongated, tubular shaftextending in a longitudinal direction, said shaft having a proximal endand a distal end; and an inflatable balloon supported along the distalend of the shaft, the balloon when inflated including first and secondspaced conical end sections and a working surface between the conicalsections, the balloon further including at least one radiopaque markingidentifying the transition from the conical end section to the workingsurface.1.2 The catheter of paragraph 1.1, wherein the at least one radiopaquemarking comprises a first radiopaque marking at a first transitionbetween the first conical end section and the working surface, andfurther including a second radiopaque marking at a second transitionbetween the second conical end section and the working surface.1.3 The catheter of any of the foregoing paragraphs, wherein the atleast one marking comprises a strip.1.4 The catheter of any of the foregoing paragraphs, further including aplurality of radiopaque markings in the form of strips.1.5 The catheter of paragraph 1.4, wherein the strips extend at leastpartially in a longitudinal direction between the first and secondconical end sections.1.6 The catheter of paragraphs 1.4 or 1.5, wherein the strips compriseannular bands.1.7 The catheter of any of the foregoing paragraphs, wherein at leasttwo spaced radiopaque markings are provided on each conical end section,including one adjacent a distal portion and a proximal portion of eachconical end section.1.8 The catheter of any of the foregoing paragraphs, wherein the balloonincludes a barrel section between the first and second conical endsections, and further including a plurality of radiopaque markings onthe barrel section.1.9 The catheter of any of the foregoing paragraphs, wherein the markingcomprises a first pattern on the conical end sections and furtherincluding a second, different pattern on the working surface.1.10 The catheter of any of the foregoing paragraphs, wherein the atleast one marking is selected from the group consisting of a pattern, astrip, a brand, a logo, a letter, a number, a word, or combinationsthereof.1.11 The catheter of any of the foregoing paragraphs, wherein theidentifier comprises a scale.1.12 The catheter of any of the foregoing paragraphs, wherein theballoon includes a drug.1.13 The catheter of paragraph 1.12, wherein the drug corresponds to thelocation of the radiopaque marking.1.14 The catheter of paragraph 1.12, wherein the drug corresponds toother than the location of the radiopaque marking.1.15 The catheter of paragraph 1.12, wherein the radiopaque markingcomprises the drug formulated to include a radiopacifier.1.16 A balloon having a drug carried on a working surface of the balloonwall and a radiopaque identifier identifying the location of the drug onthe balloon.1.17 The balloon of paragraph 1.16, wherein the radiopaque identifiercomprises a radiopaque material mixed with a formulation comprising thedrug.1.18 The balloon of paragraph 1.16, wherein the working surface is alonga barrel section of the balloon, and the radiopaque identifier is on oneor both cone sections of the balloon.2.1 A balloon catheter, comprising: an elongated, tubular shaftextending in a longitudinal direction, said shaft having a proximal endand a distal end; and an inflatable balloon supported along the distalend of the shaft, the balloon when inflated including a generallycylindrical barrel section forming a working surface, and generallyconical end sections that do not form a part of the working surface, theballoon further including at least one radiopaque identifier forindicating the relative position of the working surface, said identifierbeing provided on at least one of the conical end sections of theballoon so as to define the extent of the working surface.2.2 The catheter of paragraph 2.1, wherein the identifier comprises amarking.2.3 The catheter of paragraph 2.1 or 2.2, wherein a first marking isprovided at a first transition between the first conical section endsection and the working surface and a second marking is provided at asecond transition between the second end section and the workingsurface.2.4 The catheter of paragraph 2.2 or 2.3, wherein the marking comprisesa strip.2.5 The catheter of any of the foregoing paragraphs, wherein theidentifier comprises a longitudinal strip extending between an end ofthe balloon and the barrel section.2.6 The catheter of any of the foregoing paragraphs, further including aplurality of identifiers.2.7 The catheter of paragraph 2.6, wherein each of the plurality ofidentifiers comprises a longitudinally extending strip.2.8 The catheter of paragraph 2.6 or 2.7, wherein the identifierscomprise annular bands.2.9 The catheter of paragraph 2.6 or paragraph 2.8 as dependent onparagraph 2.6, wherein the identifiers comprise longitudinally extendingstrips.2.10 The catheter of any of the foregoing paragraphs 2.1 to 2.9, whereinat least two spaced radiopaque identifiers are provided on each endsection.2.11 The catheter of any of the foregoing paragraphs 2.1 to 2.10,further including at least one radiopaque identifier on the barrelsection.2.12 The catheter of any of the foregoing paragraphs 2.1 to 2.11,wherein the identifier is a first identifier comprising a first pattern,and further including a second identifier comprising a second, differentpattern.2.13 The catheter of any of the foregoing paragraphs 2.1 to 2.12,wherein the identifier includes at least one letter or number.2.14 The catheter of any of the foregoing paragraphs 2.1 to 2.13,wherein the identifier comprises a logo.2.15 The catheter of any of the foregoing paragraphs 2.1 to 2.14,wherein the identifier comprises a scale.2.16 The catheter of any of the foregoing paragraphs 2.1 to 2.15,further including a drug on the balloon.3.1 An inflatable balloon for use in connection with a catheter,comprising: an inflatable body including a working surface extending ina longitudinal direction between a first end and a second end, the bodyhaving at least one radiopaque identifier provided along the body foridentifying at least a first end of the working surface, the radiopaqueidentifier having a first radiographic quality for identifying thelocation of the first end of the working surface and a secondradiographic quality at a location other than at the first end of theworking surface.3.2 The balloon of paragraph 3.1, wherein the second radiographicquality is provided for identifying the second end of the workingsurface.3.3 The catheter of paragraph 3.2, wherein the first radiographicquality and the second radiographic quality are substantially the same.3.4 The balloon of paragraph 3.1, wherein the radiopaque identifiercomprises a marking.3.5 The balloon of paragraph 3.1, wherein the radiopaque identifierfollows a generally helical path from the first end to the second end ofthe working surface.3.6 The balloon of paragraph 3.1, wherein the identifier comprises aplurality of helical identifiers extending along the working surface.3.7 The balloon of paragraph 3.1, wherein the identifier comprises aradiopaque filament.3.8 The balloon of paragraph 3.7, wherein the filament is woundhelically along at least a portion of the working surface of theballoon.3.9 The balloon of any of the foregoing paragraphs 3.1 to 3.8, furtherincluding a drug on the balloon.3.16 A balloon for use in connection with a catheter, comprising: a bodyhaving an outer surface and at least one winding extending along theouter surface of the balloon, said balloon having a radiopaque quality.3.17 The balloon of paragraph 3.16, wherein the winding comprises aradiopaque filament.3.18 The balloon of any of the foregoing paragraphs, wherein theradiopaque identifier comprises a helical pattern or a diamond pattern.3.19 A catheter including the balloon of any of the foregoingparagraphs.3.20 An inflatable balloon for use in connection with a cathetercomprising a radiopaque identifier comprising a helical pattern or adiamond pattern.4.1 A balloon catheter for use in connection with a guidewire,comprising: an elongated, tubular shaft extending in a longitudinaldirection, said shaft having a proximal end and a distal end; aninflatable balloon supported along the distal end of the shaft, theballoon when inflated including first and second spaced ends and aworking surface between the ends; and at least one wire including atleast a radiopaque portion for identifying the location of workingsurface of the balloon.4.2 The catheter of paragraph 4.1, wherein said wire comprises amaterial having a shape memory for adjusting between a first state and asecond state.4.3 The catheter of paragraph 4.1 or 4.2, wherein the at least one wireextends generally in the longitudinal direction.4.4 The catheter of any of the foregoing paragraphs 4.1 to 4.3, whereinthe radiopaque portion is elongated.4.5 The catheter of any of the foregoing paragraphs 4.1 to 4.4, whereinthe wire at least partially comprises a polymer.4.6 The catheter of any of the foregoing paragraphs 4.1 to 4.5, whereinthe at least one wire is at least partially elastic.4.7 The catheter of any of the foregoing paragraphs 4.1 to 4.6,comprising: a plurality of wires extending generally in the longitudinaldirection, at least one of the wires including at least a radiopaqueportion for identifying the location of working surface of the balloon.4.8 The catheter of any of the foregoing paragraphs 4.1 to 4.7, whereinat least one wire extends along an outer surface of the balloon.4.9 The catheter of any of the foregoing paragraphs 4.1 to 4.8, whereinat least one wire extends along an inner surface of the balloon.4.10 The catheter of any of the foregoing paragraphs 4.1 to 4.9, whereinat least one wire extends from the first end to the second end of theballoon.4.11 The catheter of any of the foregoing paragraphs 4.1 to 4.10,wherein the radiopaque portion of at least one wire extends along aportion of the balloon corresponding to the working surface.4.12 The catheter of any of the foregoing paragraphs 4.1 to 4.11,wherein the radiopaque portion of at least one wire extends along otherthan along the portion of the balloon corresponding to the workingsurface.4.13 The catheter of paragraph 4.7 or any of paragraphs 4.8 to 4.12 asdependent on paragraph 4.7, wherein the wires are spaced substantiallyequidistantly around a circumference of the balloon.4.14 The catheter of any of the foregoing paragraphs 4.1 to 4.13,wherein the wire includes a compliant or semi-compliant portion.4.15 The catheter of any of the foregoing paragraphs 4.1 to 4.14,wherein at least one end of the at least partially radiopaque wire isattached to a bond connecting the balloon to the shaft.4.16 The catheter of any of the foregoing paragraphs 4.1 to 4.15,further including a drug provided on the balloon.4.17 The catheter of any of the foregoing paragraphs 4.1 to 4.16,wherein at least one wire at least partially comprises a material havinga shape memory for adjusting between a first state and a second state.4.18 The catheter of paragraph 4.2 or 4.17, wherein the shape memorymaterial comprises NITINOL.5.1 A balloon catheter adapted for use with a guidewire, comprising: anelongated, tubular shaft extending in a longitudinal direction, saidshaft having a proximal end and a distal end; an inflatable balloonsupported along the distal end of the shaft, the balloon when inflatedincluding first and second spaced ends and a working surface between theends; and an insert located within the interior compartment of theballoon, the insert including at least a radiopaque portion separatefrom the shaft.5.2 The catheter of paragraph 5.1, wherein the insert is adapted formoving relative to the shaft.5.3 The catheter of paragraph 5.1 or 5.2, wherein the insert extendsfrom a first end of the balloon to one end of the working surface.5.4 The catheter of any of the foregoing paragraphs 5.1 to 5.3, whereinthe insert comprises a tube made at least partially of a radiopaquematerial.5.5 The catheter of any of the foregoing paragraphs 5.1 to 5.4, whereinthe insert comprises at least one finger.5.6 The catheter of paragraph 5.5, wherein the finger includes aradiopaque end portion.5.7 The catheter of any of the foregoing paragraphs 5.1 to 5.6, whereinthe insert comprises a plurality of fingers adapted for moving from aretracted condition to an expanded condition when the balloon isinflated.5.8 The catheter of any of the foregoing paragraphs 5.1 to 5.7, furtherincluding a retractable sheath at least partially covering the insert.5.9 The catheter of any of the foregoing paragraphs 5.1 to 5.8, whereinthe insert comprises a wire.5.10 The catheter of paragraph 5.9, wherein the wire includes aradiopaque portion corresponding to the working surface.5.11 The catheter of paragraph 5.10, wherein the wire extends from thefirst end to the second end of the balloon, and the radiopaque portioncomprises an intermediate portion of the wire.5.12 The catheter of paragraph 5.10 or 5.11, wherein the wire extendsfrom the first end to the second end of the balloon, and the radiopaqueportion comprises an end portion of the wire.5.13 The catheter of any of the foregoing paragraphs 5.1 to 5.12,wherein at least one end of the insert is connected at a location wherethe balloon connects to the tubular shaft.5.14 The catheter of any of the foregoing paragraphs 5.1 to 5.13,wherein the insert comprises an annular band.5.15 The catheter of any of the foregoing paragraphs 5.1 to 5.14,wherein the insert includes perforations.5.16 The catheter of any of the foregoing paragraphs 5.1 to 5.15,wherein the insert comprises a material having a shape memory.5.17 The catheter of any of the foregoing paragraphs 5.1 to 5.16,further including a drug on the balloon.6.1 A parison for being blow molded into a medical balloon for acatheter, comprising: a first tubular layer having a functionalmodification; and a second tubular layer adapted for bonding with thefirst tubular layer to form the blow molded balloon.6.2 The parison of paragraph 6.1, wherein the first layer is external tothe second layer.6.3 The parison of paragraph 6.1, wherein the first layer is internal tothe second layer.6.4 The parison of any of the foregoing paragraphs, wherein thefunctional modification comprises a radiopaque strip.6.5 The parison of paragraph 6.4, wherein the strip comprises acircumferential band.6.6 The parison of paragraph 6.4 or 6.5, wherein the strip extendsbetween a first end and a second end of the first layer.6.7 The parison of any of the foregoing paragraphs, wherein the firsttubular layer is spaced from the second tubular layer.6.8 The parison of any of the foregoing paragraphs, wherein thefunctional modification is selected from the group consisting of anadded radiopacifier, a surface pattern, an etching, one or moreperforations, and combinations of the foregoing.6.9 A medical balloon formed by the parison of any of the foregoingparagraphs, comprising: a tubular, inflatable body comprising a wall,the body including first and second generally conical ends and agenerally cylindrical barrel section between the generally conical endsand providing a working surface.6.10 The balloon of paragraph 6.9, wherein the first layer extends fromthe first end to the second end of the balloon.6.11 The balloon of paragraph 6.9, wherein the first layer extends alongonly the working surface.6.12 The balloon of any of paragraphs 6.9 to 6.11, wherein the firstlayer extends along an entire circumference of a portion of the wall.6.13 The balloon of any of paragraphs 6.9 to 6.12, wherein the firstlayer extends along the full circumference of the wall.6.14 The balloon of any of paragraphs 6.9 to 6.13, wherein the wallincludes first and second spaced shoulders, and wherein the first layeris positioned between the shoulders.6.15 The balloon of any of paragraphs 6.9 to 6.14, wherein the first andsecond layers both extend from a first end to a second end of theballoon.6.16 The balloon of any of paragraphs 6.9 to 6.15, further comprising anat least partially radiopaque tube positioned over the barrel sectionand extending substantially along the working surface.6.17 The balloon of paragraph 6.16, further including first and secondshoulders adjacent the proximal and distal ends of the radiopaque tube.6.18 The balloon of paragraph 6.16 or 6.17, wherein the entire tube isradiopaque.7.1 A balloon catheter, comprising: an elongated, tubular shaft having aproximal end and a distal end; and a balloon positioned along the distalend of the shaft, a portion of a wall of the balloon partiallycomprising a coextruded radiopaque material.7.2 The catheter of paragraph 7.1, wherein the radiopaque portioncomprises at least one strip extending along a working surface of theballoon.7.3 The catheter of paragraph 7.1 or 7.2, wherein the radiopaque portioncomprises at least one strip extending along a full length surface ofthe balloon.7.4 The catheter of any of paragraphs 7.1 to 7.3, wherein the radiopaqueportion comprises at least one strip extending along a first conesection of the balloon.7.5 The catheter of paragraph 7.4, wherein the radiopaque portioncomprises at least one strip extending along a second cone section ofthe balloon.7.6 The catheter of any of paragraphs 7.1 to 7.5, wherein the balloonincludes a plurality of radiopaque portions.7.7 The catheter of paragraph 7.6, wherein each of the plurality ofradiopaque portions comprises a longitudinal strip.7.8 The catheter of paragraph 7.7, wherein the strips extend at leastalong a working surface of the balloon.7.9 The catheter of any of paragraphs 7.6 to 7.8, wherein the pluralityof radiopaque portions are spaced apart in a circumferential direction.7.10 The catheter of any of the foregoing paragraphs 7.1 to 7.9, whereinthe balloon includes a barrel section and conical sections at each endof the barrel section, and wherein the radiopaque portion is provided onthe barrel section.7.11 The catheter of any of the foregoing paragraphs 7.1 to 7.10,wherein the balloon includes a barrel section and conical sections ateach end of the barrel section, and wherein the radiopaque portion isprovided on one or both of the cone sections.7.12 The catheter of any of the foregoing paragraphs 7.1 to 7.11,wherein the radiopaque portion comprises a layer of the balloon wall.7.13 The catheter of paragraph 7.12, wherein the layer comprises aninner layer.7.14 The catheter of paragraph 7.12 or 7.13, wherein the layer comprisesan outer layer.7.15 The catheter of paragraph 7.14, wherein the outer layer is etched.7.16 The catheter of any of paragraphs 7.12 to 7.15, wherein the balloonincludes a barrel section and conical sections at each end of the barrelsection, and the layer extends along the entire barrel section.7.17 The catheter of any of paragraphs 7.12 to 7.16, wherein the balloonincludes a barrel section and conical sections at each end of the barrelsection, and the layer extends along the entirety of one or both of theconical sections.7.18 The catheter of any of the foregoing paragraphs 7.1 to 7.17,wherein all portions of the wall comprise coextruded radiopaquematerial.7.19 The catheter of any of the foregoing paragraphs 7.1 to 7.18,further including a drug on the balloon.7.20 The catheter of any of the foregoing paragraphs 7.1 to 7.19,wherein the radiopaque material comprises ePTFE.8.1 A balloon catheter, comprising: a shaft extending in a longitudinaldirection, said shaft having a proximal end and a distal end, andsupporting at least one radiopaque identifier; an inflatable balloonsupported along the distal end of the shaft, the balloon when inflatedincluding a working surface; and an actuator for aligning at least oneend of the working surface with the at least one radiopaque identifier.8.2 The catheter of paragraph 8.1, wherein the actuator includes a firstposition corresponding to a deflated state of the balloon and a secondposition corresponding to the inflated state of the balloon.8.3 The catheter of paragraph 8.1 or 8.2, wherein the actuator comprisesa spring.8.4 The catheter of any of the foregoing paragraphs 8.1 to 8.3, whereinthe spring comprises a leaf spring.8.5 The catheter of any of the foregoing paragraphs 8.1 to 8.4, whereinthe actuator comprises a plurality of springs spaced circumferentiallyabout the catheter.8.6 The catheter of any of the foregoing paragraphs 8.1 to 8.5, whereina first portion of the actuator is fixed to the balloon and a secondportion of the actuator is adapted for movement relative to the shaft.8.7 The catheter of paragraph 8.6, wherein the first portion of theactuator is captured between two layers on the wall of the balloon.8.8 The catheter of paragraph 8.6 or 8.7, wherein the shaft includes achannel for at least partially receiving the second portion of theactuator.8.9 The catheter of any of the foregoing paragraphs 8.1 to 8.8, furtherincluding a stop for stopping the movement of the actuator.8.10 The catheter of any of the foregoing paragraphs 8.1 to 8.9, whereinthe radiopaque identifier comprises a marker attached to the shaft.8.11 The catheter of any of the foregoing paragraphs 8.1 to 8.10,wherein the radiopaque identifier comprises an insert positioned withinthe interior compartment of the balloon.8.12 The catheter of any of the foregoing paragraphs 8.1 to 8.11,wherein the actuator is a first actuator for aligning a distal end ofthe working surface with the radiopaque identifier, and furtherincluding a second actuator for aligning a proximal end of the workingsurface with the radiopaque identifier.8.13 The catheter of paragraph 8.12, wherein each of the first andsecond actuators comprise a plurality of springs.8.14 The catheter of any of the foregoing paragraphs, wherein theradiopaque identifier comprises a first marking and a second marking,and wherein the actuator is a first actuator for aligning a distal endof the working surface with the first marking, and further including asecond actuator for aligning a proximal end of the working surface withthe second marking.8.15 The balloon catheter of any of the foregoing paragraphs 8.1 to8.14, comprising: a shaft extending in a longitudinal direction, saidshaft having a proximal end and a distal end, and supporting first andsecond radiopaque identifiers; a first actuator for aligning a first endof the working surface with the first radiopaque marking; and a secondactuator for aligning a second end of the working surface with thesecond radiopaque identifier.8.16 The balloon catheter of any of the foregoing paragraphs 8.1 to8.15, comprising: a shaft for carrying the balloon, the shaft includingat least one channel formed in an outer portion of a wall of the shaft;and an actuator having a first end connected to the balloon and a secondend at least partially positioned in the channel.8.17 The balloon catheter of any of the foregoing paragraphs 8.1 to8.16, comprising: a shaft for carrying the balloon, the shaft includinga plurality of channels formed in an outer portion of the wall of theshaft.8.18 The catheter of paragraph 8.17, further including an actuatorhaving a first end connected to the balloon and a second end positionedin at least one of the channels.8.19 The catheter of any of the foregoing paragraphs 8.1 to 8.8,comprising: a spring connected to a wall of the balloon.8.20 The catheter of paragraph 8.19, wherein the spring is at leastpartially radiopaque.8.21 The catheter of paragraph 8.19 or 8.20, wherein the spring isconnected to a conical section of the wall of the balloon.8.22 The balloon catheter of any of the foregoing paragraphs 8.1 to8.21, wherein the balloon includes a drug.9.1 A balloon catheter for use with a guidewire, comprising: anelongated, tubular shaft extending in a longitudinal direction, saidshaft having a proximal end and a distal end; an inflatable balloonconnected to the distal end of the shaft, the balloon including aworking surface; a radiopaque identifier for identifying the workingsurface; and a receiver adjacent the proximal end of the shaft andadapted for allowing the shaft to move relative to the receiver in atleast the longitudinal direction.9.2 The catheter of paragraph 9.1, wherein the shaft carries a stop, andthe receiver further includes a recess for receiving the stop, saidrecess having a dimension in the longitudinal direction that is greaterthan a corresponding dimension of the stop.9.3 The catheter of paragraph 9.2, further including a tube forsupplying an inflation fluid to inflate the balloon, said tube beingconnected to the receiver and generally coaxial with the shaft, andwherein the stop forms a seal with the recess to prevent the inflationfluid from passing around the shaft.9.4 The catheter of paragraph 9.3, wherein the seal comprises an O-ringarranged coaxially with the shaft.9.5 The catheter of paragraph 9.1, wherein the radiopaque identifier isseparate from the shaft.9.6 The catheter of paragraph 9.5, wherein the radiopaque identifiercomprises an insert positioned within the interior compartment of theballoon.9.7 The catheter of paragraph 9.6, wherein the insert comprises atubular sleeve arranged coaxially with the shaft.9.8 The catheter of paragraph 9.6, wherein the insert comprises a firstinsert at a proximal end of the balloon and a second insert at a distalend of the balloon.9.9 The catheter of paragraph 9.1, further including a guidewire forpositioning in the shaft.9.10 A hub for a balloon catheter having an elongated, tubular shaftextending in a longitudinal direction, said shaft having a proximal endand a distal end, and an inflatable balloon connected to the distal endof the shaft for being inflated by an inflation fluid, comprising: abody including a receiver for receiving a proximal portion of the shaftand adapted for allowing the shaft to move relative to the receiver inat least the longitudinal direction; and a stop for restraining themovement of the shaft relative to the body in the longitudinaldirection.9.11 The hub of paragraph 9.10, wherein the body includes a guidewireport arranged in communication with the receiver, and further includingan inflation port for introducing the inflation fluid for inflating theballoon.9.12 The hub of paragraph 9.10, wherein the receiver further includes arecess for receiving the stop, said recess having a dimension in thelongitudinal direction that is greater than a corresponding dimension ofthe stop.9.13 The hub of paragraph 9.12, wherein the stop forms a seal with therecess to prevent the inflation fluid from passing.9.14 The hub of paragraph 9.10, wherein the stop comprises an O-ring.9.15 A catheter including a guidewire shaft having a distal endconnected to a balloon and at a proximal end mounted for slidingmovement.9.16 The catheter of any of the foregoing paragraphs, further includinga drug on the balloon.9.17 A catheter comprising a hub for receiving a proximal end of aguidewire shaft, the shaft being adapted to slidably move in arestrained manner relative to the hub.10.1 A balloon catheter, comprising: an elongated tubular shaft having aproximal end and a distal end spaced apart in a longitudinal direction,the shaft along a distal portion including at least one radiopaqueidentifier, said distal portion being formed of a material resistant toelongation in the longitudinal direction; and an inflatable,non-compliant balloon extending over the distal portion of the shaft.10.2 The catheter according to paragraph 10.1, wherein the balloonincludes a generally cylindrical barrel section positioned betweengenerally conical sections, said barrel section including a workingsurface having at least one edge aligned with the radiopaque identifier.10.3 The catheter according to paragraph 10.2, wherein the radiopaqueidentifier comprises a first marker positioned at the at least one edgeof the working surface, and further including a second marker positionedat the opposite edge of the working surface in the longitudinaldirection.10.4 The catheter according to paragraph 10.2, wherein each markercomprises a radiopaque band swaged to the distal portion of the shaft.10.5 The catheter according to paragraph 10.1, wherein the distalportion of the shaft comprises a tube adapted for guiding a guidewirefrom a proximal end of the balloon to a distal end of the balloon.10.6 The catheter according to paragraph 10.1, wherein at least thedistal portion of the shaft comprises steel.10.7 The catheter according to paragraph 10.1, wherein the shaftcomprises steel.10.8 The catheter according to paragraphs 10.6 or 10.7, wherein thesteel shaft comprises a stainless steel.10.9 The catheter according to paragraphs 10.7 or 10.8, wherein thesteel shaft includes a spiral cut along a portion other than the distalportion covered by the balloon.10.10 The catheter according to paragraphs 10.7 or 10.8, wherein thesteel shaft comprises a polymer layer.10.11 The catheter according to paragraph 10.10, wherein the polymerlayer comprises an outer layer of the shaft.10.12 The catheter according to paragraph 10.1, wherein the distalportion of the shaft comprises a polymer shaft including a braid ormesh.10.13 The catheter according to paragraph 10.1, wherein the balloonincludes a generally cylindrical barrel section positioned betweengenerally conical sections, the distal portion of the shaft extendingfrom a first end of a first conical section to a second end of a secondconical section.10.14 The catheter according to paragraph 10.1, wherein thenon-compliant balloon comprises one or more inelastic fibers.10.15 The catheter according to paragraph 10.1, wherein thenon-compliant balloon comprises polyethylene terephthalate.10.16 The catheter of any of the foregoing paragraphs 10.1 to 10.15,further including a drug on the balloon.11.1 A balloon catheter, comprising: a shaft extending in a longitudinaldirection and adapted for expanding from a compressed condition to anexpanded condition in the longitudinal direction, the shaft supportingat least one radiopaque identifier; and an inflatable balloon positionedalong the shaft, the balloon when inflated including a working surfacefor aligning with the radiopaque identifier in at least the expandedcondition of the shaft.11.2 The catheter of paragraph 11.1, wherein the expandable shaftcomprises a first portion connected in tandem to an expandable element.11.3 The catheter of paragraphs 11.1 or 11.2, wherein the expandableelement comprises a spring.11.4 The catheter of paragraph 11.3, wherein the spring comprises a coilspring.11.5 The catheter of paragraphs 11.3 or 11.4, wherein the springcomprises a tension coil spring.11.6 The catheter of paragraph 11.2, wherein the expandable elementcomprises a bellows.11.7 The catheter of paragraph 11.2, wherein the expandable elementcomprises a fiber matrix.11.8 The catheter of paragraph 11.7, further including a springassociated with the fiber matrix.11.9 The catheter of any of paragraphs 11.2-11.8, wherein the expandableelement is inside an interior compartment of the balloon.11.10 The catheter of any of paragraphs 11.2-11.8, wherein theexpandable element is outside an interior compartment of the balloon.11.11 The catheter of any of paragraphs 11.2-11.10, wherein theexpandable element connects to one end of the balloon.11.12 The catheter of any of paragraphs 11.2-11.10, wherein theexpandable element connects the first portion of the shaft to a secondportion of the shaft.11.13 The catheter of any of the foregoing paragraphs 11.1 to 11.12,wherein the shaft comprises an inflation lumen for delivering aninflation fluid to the balloon.11.14 The catheter of any of the foregoing paragraphs 11.1 to 11.13,wherein the expandable shaft in at least a partially expanded conditiona port for delivering the inflation fluid to the balloon, said portbeing closed when the shaft is in a non-expanded condition.11.15 The catheter of any of the foregoing paragraphs 11.1 to 11.14,wherein the expandable shaft comprises a first expandable elementconnecting a first portion of the shaft to a second portion of theshaft, and further including a second expandable element connecting thesecond portion of the shaft to a third portion of the shaft.11.16 The catheter of paragraph 11.15, wherein the first and secondexpandable elements comprise first and second coil springs.11.17 The catheter of paragraph 11.16, wherein the first and second coilsprings have different spring constants.11.18 The catheter of any of the foregoing paragraphs 11.1 to 11.17,wherein the radiopaque identifier comprises a pair of spaced radiopaquemarkers, one positioned in alignment with a first end of the workingsurface and another positioned at a second end of the working surface.11.19 The catheter of any of paragraphs 11.15-11.18, wherein the firstand second expandable elements comprise a radiopaque material.11.20 The catheter of any of the foregoing paragraphs 11.1 to 11.19,wherein the radiopaque identifier comprises a spring.11.21 The catheter of paragraph 11.2, wherein the expandable elementcomprises a spring having a variable spring constant.11.22 The catheter of any of the foregoing paragraphs 11.1 to 11.21,wherein the shaft comprises a guidewire lumen.11.23 The catheter of any of the foregoing paragraphs 11.1 to 11.22,further including a passage adjacent the tip for receiving a guidewireexternal to the balloon.11.24 The catheter of paragraph 11.2, wherein the first portion isadjacent a distal end of the shaft.11.25 A balloon catheter, comprising: a shaft; a balloon; and anexpandable element adapted for expanding in the longitudinal directionconnecting the shaft to the balloon.11.26 The catheter of paragraph 11.25, wherein the expandable element isselected from the group consisting of a spring, a bellows, a fibermatrix, or combinations of the foregoing.11.27 The catheter of paragraph 11.25 or 26, wherein the expandableelement comprises an encapsulated spring.11.28 A balloon catheter comprising a balloon and an inflation lumenincluding an expandable element adapted for expanding in thelongitudinal direction for providing a fluid to the balloon.11.29 The catheter of any of paragraphs 11.25-11.28, wherein theexpandable element comprises a radiopaque material.11.30 The catheter of any of the foregoing paragraphs 11.1 to 11.29,further including a drug on the balloon.12.1 A balloon catheter, comprising: an elongated, tubular shaftextending in a longitudinal direction, said shaft having a proximal endand a distal end; and a balloon having an inflation compartment formed aballoon wall including a working surface, and further including at leastone chamber adjacent to the working surface adapted for receiving anidentifier for identifying the location of the working surface.12.2 The balloon catheter of paragraph 12.1, wherein the shaft includesa first lumen for supplying a fluid to the chamber.12.3 The balloon catheter of paragraph 12.2, wherein the shaft includesa port between the first lumen and the chamber.12.4 The balloon catheter of paragraph 12.2, wherein the shaft includesa second lumen for supplying a fluid to an interior compartment of theballoon.12.5 The balloon catheter of paragraph 12.4, wherein the shaft includesa port between the second lumen and the interior compartment.12.6 The balloon catheter of any of the foregoing paragraphs 12.1 to12.5, wherein the identifier comprises a contrast agent.12.7 The balloon catheter of any of the foregoing paragraphs 12.1 to12.6, wherein the contrast agent comprises a material selected from thegroup consisting of a radiopacifier, polyvinyl acetate, cellulose, afluid, a liquid, a solid, a powder, or combinations of the foregoing.12.8 The balloon catheter of any of the foregoing paragraphs 12.1 to12.7, wherein the chamber comprises a first chamber at a proximal end ofthe balloon, and further including a second chamber at a distal end ofthe balloon.12.9 The balloon catheter of paragraph 12.8, wherein the second chamberis adapted for receiving the identifier from a lumen in the shaft influid communication with the first chamber via a port.12.10 The balloon catheter of any of the foregoing paragraphs 12.1 to12.9, wherein the chamber is generally annular.12.11 The balloon catheter of any of the foregoing paragraphs 12.1 to12.10, wherein the chamber is positioned between a transition from abarrel section to a conical section of the balloon and an end of theballoon.12.12 The balloon catheter of any of the foregoing paragraphs 12.1 to12.11, wherein the chamber is provided by a film attached to the balloonwall.12.13 The balloon catheter of any of the foregoing paragraphs 12.1 to12.12, wherein the chamber is embedded in the balloon wall.12.14 The balloon catheter of any of the foregoing paragraphs 12.1 to12.13, wherein the chamber is provided by a film extending between theballoon wall and an outer surface of the shaft.

While the disclosure presents certain embodiments to illustrate theinventive concepts, numerous modifications, alterations, and changes tothe described embodiments are possible without departing from the sphereand scope of the present invention, as defined in the appended claims.For example, any ranges and numerical values provided in the variousembodiments are subject to variation due to tolerances, due tovariations in environmental factors and material quality, and due tomodifications of the structure and shape of the balloon, and thus can beconsidered to be approximate and the term “approximately” means that therelevant value can, at minimum, vary because of such factors.Accordingly, it is intended that the present invention not be limited tothe described embodiments, but that it has the full scope defined by thelanguage of the following claims, and equivalents thereof.

The invention claimed is:
 1. A medical balloon formed by a parison forbeing blow molded into the medical balloon for a catheter, the parisoncomprising a first tubular layer having a functional modification and asecond tubular layer adapted for bonding with the first tubular layer toform the blow molded balloon, the medical balloon comprising: a tubular,inflatable body comprising a wall, the body including first and secondgenerally conical ends and a generally cylindrical barrel sectionbetween the generally conical ends and providing a working surface,wherein the wall includes first and second spaced shoulders, and whereinthe first layer is positioned between the shoulders.
 2. The balloon ofclaim 1, wherein the first and second layers both extend from a firstend to a second end of the balloon.
 3. The balloon of claim 1, furthercomprising an at least partially radiopaque tube positioned over thebarrel section and extending substantially along the working surface. 4.The balloon of claim 1, wherein the first layer extends from the firstconical end to the second conical end of the balloon.
 5. The balloon ofclaim 1, wherein the first layer extends along only the working surface.6. The balloon of claim 1, wherein the first layer extends along anentire circumference of a portion of the wall.
 7. The balloon of claim1, wherein the first layer extends along the full circumference of thewall.
 8. A medical balloon formed by a parison for being blow moldedinto the medical balloon for a catheter, the parison comprising a firsttubular layer having a functional modification and a second tubularlayer adapted for bonding with the first tubular layer to form the blowmolded balloon, the medical balloon comprising: a tubular, inflatablebody comprising a wall, the body including first and second generallyconical ends and a generally cylindrical barrel section between thegenerally conical ends and providing a working surface, an at leastpartially radiopaque tube positioned over the barrel section andextending substantially along the working surface and further includingfirst and second shoulders adjacent a proximal end and a distal end ofthe radiopaque tube, the shoulders serving to retain the radiopaque tubeagainst movement in a longitudinal direction.
 9. The balloon of claim 3,wherein the entire tube is radiopaque.